My Community

Hi,

I am now using vasp.6.2.1, and I wanted to use a python add-on to extract irreducible representations of bands. This needs to query symmetry operators from OUTCAR as inputs. I found that vasp.6.2.1 does not supply explicit symmetry operators in OUTCAR anymore. Are there any parameters in INCAR, or any ways I can extract that information from outputs from vasp? Thanks in advance.

Could you be more specific, which output you expect? I have compared the output generated by version 5.4.4 with the current one and I don't see any significant differences in the symmetry related part.

Hi, thanks for replying! I am using openACC GPU version of vasp.6.2.1 compiled by Nersc.

In vasp.5.4.4, we can look for spacegroup operators by keyword "irot" in OUTCAR. The result will be something as the follow.
Space group operators:
irot det(A) alpha n_x n_y n_z tau_x tau_y tau_z
1 1.000000 0.000001 1.000000 0.000000 0.000000 0.000000 0.000000 0.000000
2 1.000000 120.000000 0.000000 0.000000 -1.000000 0.000000 0.000000 0.000000
3 1.000000 120.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000
4 -1.000000 179.999999 1.000000 -0.000000 0.000000 0.000000 0.000000 0.000000
5 -1.000000 180.000000 0.500000 -0.866025 0.000000 0.000000 0.000000 0.000000
6 -1.000000 179.999999 -0.500000 -0.866025 0.000000 0.000000 0.000000 0.000000

While in vasp.6.2.1, the above keyword finds nothing. The related spacegroup information is like:
=====================================================================
Subroutine PRICEL returns:
Original cell was already a primitive cell.


Routine SETGRP: Setting up the symmetry group for a
hexagonal supercell.


Subroutine GETGRP returns: Found 6 space group operations
(whereof 6 operations were pure point group operations)
out of a pool of 24 trial point group operations.


The overall configuration has the point symmetry C_3v.


Subroutine INISYM returns: Found 6 space group operations
(whereof 6 operations are pure point group operations),
and found 1 'primitive' translations

Okay this particular output is actually still in the code, it is just deactivated. If you search in the file mkpoints.F for the call to SET_SPINROT_WRAPPER, you'll see that the last argument is -1 (no output). When you replace this by IU6, this output is written again.

Thanks a lot! I will try it out.